[[File:Porcupine Mountains Wilderness State Park in spring 2023 - 304.jpg|thumb|Sandy glacial diamicton (till) bluff on the shore of Lake Superior near Speakers Cabin.]] '''Diamicton''' (also '''diamict''') (from Greek δια (''dia-'') 'through' and μικτός (''meiktós'') 'mixed') is any terrigenous sediment (a sediment resulting from dry-land erosion) that is unsorted to poorly sorted and contains particles ranging in size from clay to boulders, suspended in an unconsolidated matrix of mud or sand. Today, the word has strong connotations to glaciation but can be used in a variety of geological settings.<ref name="JacksonOthers2005a">Jackson, J.A., J. Mehl, and K. Neuendorf (2005) ''Glossary of Geology'' American Geological Institute, Alexandria, Virginia. 800 pp. {{ISBN|0-922152-76-4}}</ref><ref name="BennettOthers2009a">Bennett, M.R., and N.F. Glasser (2009) ''Glacial Geology: Ice Sheets and Landforms'', 2nd Ed. John Wiley & Sons, Ltd., New York, New York. 400 pp. {{ISBN|978-0470516911}}</ref><ref name="Tucker2003a">Tucker, M.E. (2003) ''Sedimentary Rocks in the Field'' John Wiley & Sons, Ltd., New York, New York. 244 pp. {{ISBN|978-0470851234}}</ref>
The term was proposed by Richard Flint and others<ref name="FlintOthers1960a">Flint, R.F., J.E. Sanders, and J. Rodgers (1960) ''Diamictite, a substitute term for symmictite'' Geological Society of America Bulletin. 71(12):1809–1810.</ref> as a purely descriptive term, devoid of any reference to a specific origin or depositional environment. Although the term is most commonly applied to unsorted glacial deposits (i.e., glacial till), other processes that create diamictons are solifluction, landslides, and debris flows.<ref name="BennettOthers2009a"/><ref name="Tucker2003a"/>
The term can generally be applied to types of siliciclastic sediments and sedimentary rocks, and acts as a root name for sediments that are poorly sorted and contain a wide clast size range. Sediments given this root often transverse the boundary of siliciclastic rudaceous, arenaceous and argillaceous sediments. Diamicton is the unconsolidated equivalent of ''diamictite''.,<ref name="BennettOthers2009a" /><ref name="Tucker2003a" /> otherwise known as lithified diamicton.
The British Geological Survey (BGS), based in the UK, defines diamicton to comprise over 50% pre-existing siliceous rock clasts, but otherwise having undefined composition.<ref>{{Cite web |title=BGS Rock Classification Scheme - Details forDiamicton - A type of siliciclastic sediment and sedimentary rock. Sediments that are poorly sorted and contain a wide range of clast sizes can be given this root name. The strict descriptive definition relates to range of particle size and not to relative abundance of any or all size classes. These sediment types therefore traverse the boundary of siliciclastic rudaceous, arenaceous and argillaceous sediments. This is the unconsolidated equivalent of diamictite. British Geological Survey Research Report RR/99/03, section 2 and figs. 2, 3 and 5.{{!}} British Geological Survey (BGS) |url=https://webapps.bgs.ac.uk/bgsrcs/rcs_details.cfm?code=DMTN#:~:text=Diamicton%20-%20A%20type%20of%20siliciclastic,any%20or%20all%20size%20classes. |access-date=2024-03-24 |website=webapps.bgs.ac.uk}}</ref>
== Types == Till is diamicton deposited specifically by the underneath of a glacier<ref>{{Cite web |title=BGS Lexicon of Named Rock Units - Result Details |url=https://webapps.bgs.ac.uk/lexicon/lexicon.cfm?pub=TILL |access-date=2025-12-15 |website=webapps.bgs.ac.uk}}</ref><ref>{{Cite journal |last=Lawson |first=Daniel E. |date=January 1981 |title=Distinguishing characteristics of Diamictons at the Margin of the Matanuska Glacier, Alaska |url=https://www.cambridge.org/core/journals/annals-of-glaciology/article/distinguishing-characteristics-of-diamictons-at-the-margin-of-the-matanuska-glacier-alaska/BA69DC907D62B59865B09FA3165EADA9 |journal=Annals of Glaciology |language=en |volume=2 |pages=78–84 |doi=10.3189/172756481794352379 |issn=0260-3055 |quote=Melt-out till mostly inherits fabric, internal structure, and grain-size distribution from its debris-laden basal ice source.|url-access=subscription }}</ref> and colluvium is diamicton deposited by down slope non-fluvial processes.<ref>{{Cite journal |last=Lawson |first=Daniel E. |date=January 1981 |title=Distinguishing characteristics of Diamictons at the Margin of the Matanuska Glacier, Alaska |url=https://www.cambridge.org/core/journals/annals-of-glaciology/article/distinguishing-characteristics-of-diamictons-at-the-margin-of-the-matanuska-glacier-alaska/BA69DC907D62B59865B09FA3165EADA9 |journal=Annals of Glaciology |language=en |volume=2 |pages=78–84 |doi=10.3189/172756481794352379 |issn=0260-3055 |quote=Sediment flow deposits and ice-slope colluvium (deposited by ablational slope processes) have properties developed by resedimentation mechanisms.|url-access=subscription }}</ref>
Olistostrome differs from diamicton by being derived from submarine (marine or lacustrine) depositional conditions (see turbidities).<ref>{{Cite journal |last=St-Onge |first=Denis A. |last2=Lajoie |first2=Jean |date=November 1986 |title=The late Wisconsinan olistostrome of the lower Coppermine River valley, Northwest Territories |url=https://cdnsciencepub.com/doi/10.1139/e86-157 |journal=Canadian Journal of Earth Sciences |volume=23 |issue=11 |pages=1700–1708 |doi=10.1139/e86-157 |issn=0008-4077}}</ref>
== See also ==
* Alluvium - sedimentary deposits that are the results of fluvial transport processes. * Eluvium - sedimentary deposits that are the results of in situ rock weathering. * Periglacial Head
== References == <references />
==External links== * [http://academic.emporia.edu/aberjame/ice/gloss.htm Ice Age Terms] {{Webarchive|url=https://web.archive.org/web/20050404050359/http://academic.emporia.edu/aberjame/ice/gloss.htm |date=2005-04-04 }}
Category:Sediments
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